Dooe-spkiitg



UNITED sTATEs PATENT oEEicE.

JOHN O. BLYTHE, OF GERMANTOWN, PENNSYLVANIA.

DOOR-SPRING.

Specification of Letters Patent No. 31,862, dated April 2, 1861.

To all whom t may concern:

Be it known that I, JOHN OLIVER BLYTHE, of Germantown, in the county of Philadelphia and State of Pennsylvania, have invented a new and useful Improvement in Door-Springs for Shutting Doors and also for Holding Them Open; and I do hereby declare that the following is a full, clear, and eXact description of the construction and operation of the same, referenceV being had to the annexed drawings, making a part of this specification, in which- Figure l, is a perspective view of the front side of the machine; Fig. 2, a lateral or longitudinal` View of the back side of the same; Fig. 3, a lateral View of the same side; Fig. 4., a lineal View of the machine; Fig. 5, the arm; Fig. 6, a front perspective view of the Same with door and frame; Fig. 7, a slot in the top of the door.

Fig. No. 1c is the metallic frame-c flanges-Z9 the arm and*cZ the slot in the metallic frame. No. 2-b*metallic frame iL-slot-cab-opening for spring-c elevaarin-b-to Work in and out of-b-is the arm with cam CZ at one end which is made to press against a steel lever spring on the back side of the machine, or frame, as the door is opened until passing the center the door is thrown back and held firmly openwhen not thrown so far back the door is closed by the spring-the point-g-at the other end of the arm represented inwNo. 6, of specification and lifted out of the slotc c-cut in the top of the door-is made to traverse the slot in opening and shutting the door. The spring as seen in No. 3 -and 4 is a steel lever spring secured at one end by dove tail into the elevated part of the frame at-a-a-and as seen in No. EZ-F ig. 2--of specification at the opening-a b. The spring is driven into the dove tail and forced down on the elevations-c, c -in No. 2-and then forced back to admit the cam which is secured to its place by the pin passing through the part c c a-t-o-thus: being a strong spring on the door when shut. The door is thus made also a lever to work the arm as seen in the model accompanying the drawings.

What I'cla-im as my invention and desire to secure by Letters Patent is- The peculiar construction ofthe armb-as seen in Fig. 1, No. 1., at the point marked-gin combination with other parts of the machine to effect the purposes set forth as aforestated.

JOHN OLIVER BLYTHE.

Vitnesses:

CHASE F. HELFRICHT, EDWARD T. TALEY. 

